In order to achieve the goal of miniaturization and light weight of Fourier transform spectrometer, a light-weight grid beam splitter structure was designed instead of the traditional parallel plate beam splitter. The influence of the grid edge of the grid beam splitter on spectrum reconstruction was analyzed, and the tolerance of production error was proposed. The micro-Fourier transform spectrometer was modeled and simulated, and the optimal structure of the grid beam splitter was obtained. The spectral inversion was performed by system simulation, and the restored spectrum was obtained. The spectral error introduced by the grid beam splitter was calculated. The construction and debugging of the prototype was completed, and the recovered spectrum of the actual system was obtained, which proved the feasibility of the miniaturized system. Compared with the traditional Fourier transform spectrometer, the miniaturization system has the advantages of small volume and good stability, and can be used for online monitoring.National Natural Science Foundation(No.61627819，No.61575193，No.61805239，No.61727818，No.61735018);Jilin Province Science and Technology Development Plan(No.20190303063SF，No.20180201024GX,No.20150520101JH，No.20170204077GX，No.20190101012JH,No.20160204064GX);Jilin Province Young and Middle-aged Science and Technology Innovation Leaders and Team Project(No.20190101012JH);National Fund for Applied Optics Open Fund